The present invention concerns an apparatus for handling confectionery products which can be moved in rows through several successive processes in which the products may have different periods of stay, the apparatus comprising a slat conveyor arranged above a row of process stations and provided with means for individually lifting and lowering the conveyor support of the slats, which conveyor is arranged for stepwise carrying the rows of confectionery products through a number of working positions.
The invention also concerns a method for handling confectionery products carried in rows through several successive processes where the products can stay for different periods of time, where a slat conveyor arranged above a row of process stations is carried stepwise through a number of working positions.
In the first place, the present invention concerns handling of ice cream products. As the invention has been developed in connection with and is especially applied to ice cream products, it will be explained in the following with reference to problems and circumstances by apparatuses and methods for ice cream production. However, the invention can also be used in connection with other confectionery products or food products subjected to treatment by immersion into successive vessels.
In connection with the making of ice cream products, the hardened and frozen ice product is removed from a conveyor after passing a freezer tunnel. The ice cream product, whether an ice lolly, sandwich, bar, or cone, is then carried through a handling step where it is given a final or finishing treatment before it is conveyed to a packing unit.
The invention especially concerns the handling step disposed between the freezer tunnel and the packing unit.
It is known to dip the product once or several times in a mass, often chocolate, by lifting a so-called dip cup or dip vessel up to the ice product which is suspended from a conveyor.
Another known principle is to dip the ice product once or several times in stationary vessel, typically containing chocolate. This method may also be used for immersion into several successive vessels containing different products, for example water ice products and chocolate for final treatment of the ice cream product. Also, it is known to perform a subsequent dipping into several successive vessels, that alternately contain syrup and nitrogen. Hereby several layers of different or identical types of syrup are frozen onto the ice product. This principle differs in that it is a slat with the products which is lowered into the stationary vessel.
A common feature of the handling method is that the conveyor and thereby the ice products are conveyed stepwise. Thus a row of ice products is disposed transversely of the conveyor, the products suspended from a so-called slat. When the products are carried on sequentially they are either to perform a short or a long dip in the vessel between two conveying steps. A variation in the dipping of the product is only possible within very narrow limits. Furthermore, the known methods and apparatuses are disadvantageous as they require a very long time for readjustment. Thus the so-called elevators establishing the dipping consist of a rail segment inserted between a preceding and a subsequent rail segment in which the lateral edges of the conveyor is running. When the position of such an elevator is to be exchanged, it is necessary to read just the whole machine and to exchange the preceding and the subsequent guide rails within a single section of the machine.
Furthermore, the known systems are time-consuming to readjust if at the same time slats and/or fastening means have to be exchanged. If the conveyor is to be used for products requiring another kind of holding to a slat, it will also be necessary to exchange the slats. Until now this has been a labour-intensive and slow process. Thus it has been necessary to demount all of the slat conveyor and/or disassemble and assemble the single slats.
It is a purpose of the present invention to indicate a method and a plant implying great flexibility with respect to the number of dippings in each vessel or subsequent vessels, and which implies flexibility with regard to the type of dipping used while the dipping periods may be varied also, and which system at the same time makes possible a quick readjustment of the whole handling plant.
According to the present invention this is achieved with an apparatus of the kind mentioned in the introduction which is peculiar in that the slats via first coupling means capable of being activated individually and placed at each working position and which have first engagement means displaceable between a position of engaging the slat and a position of disengaging the slat, that there is provided second coupling means with second engagement means which are also capable of being individually activated between a position of engaging the slat and a position of disengaging the slat, and that the coupling means are connected with a central control unit activating the engagement means according to a predetermined sequence.
The method according to the invention is peculiar in that said lifting means support coupling means which are activated individually at each working position in order to make engagement means engage or disengage a slat according to signals from a control unit programmed with a predetermined processing sequence.
With an apparatus and a method according to the invention it becomes possible to omit the elevator. Instead there is provided a lifting beam at each side of the conveyor. At the lower run of the slat conveyor the lifting beam supports each slat so that it may individually be brought to a lifted or a lowered position. As the first and second engagement means are capable of being activated individually, it is possible to lift and lower a slat together with the lifting means and/or to let a slat stay hanging in a lifted position irrespective of the lifting and lowering of the lifting mean.
The coupling means preferably comprise cylinder, preferably pneumatic cylinders. However, alternatively there may be used hydraulic cylinders or electrically activated cylinders. Only it is important that the cylinders are connected with a central control unit establishing the desired working sequence for the individual cylinders. Attentively, pivoting coupling means may be used which can pivot into and out of engagement with the slats.
By activation of the cylinder, the engagement means in the shape of blocks, rollers, rails or the like are displaced into and out of engagement with the slat.
The lower part of each slat with preferably be provided with rollers supported by engagement means in the form of sections of support rails. These rails are provided side by side so that the rollers will be supported hereon for the displacing of the conveyor with the slats in a raised position. By pulling the support rails back, the slat will then rest on slide blocks placed at the underside of the slat. These slide blocks supported by the lifting beam makes it possible to lift and lower the lower part of the slat when the support rail is moved to a position without engagement of the rollers.
By activating and deactivating support rails and slide blocks, respectively, it will thus be possible optionally to determine whether an individual slat in the slat conveyor is to be lifted and lowered in one working position or whether this slat in one or more subsequent working positions is to be in a lifted or lowered position. Thus it becomes possible to make the processing time at a process station shorter or longer, and the product can stay in the dipping vessel at a process station through one or more working positions.
A readjustment of the apparatus between different processes will thus not require interfering mechanically. It is only necessary to put a new control program into the control unit. The cylinders used for activation of support rail and slide block, respectively, may be controlled by electronic or electrical readjustment of the cylinders as well as the readjustment also may take place by pneumatic or hydraulic signals.
An apparatus according to the invention will be a lot more flexible than the known apparatuses. The known plants will typically be arranged for a single or a few types of production processes because of the mechanical difficulties. Because of the great flexibility implying optional process time, an apparatus according to the invention will make it possible to readjust the apparatus to manufacture different kinds of products just by exchanging the program controlling the cylinders and possibly at the same time exchanging the process stations.
By the making of ice cream products, the process stations will typically comprise dipping vessels which may contain nitrogen, syrup, chocolate and/or other materials used for coating a product, or containers with materials for dry coating, as for example nuts, desiccated coconut, and the like. The process stations will then be provided in the shape of open vessels wherein the products are dipped. The dipping time can be made shorter or longer whereby it becomes possible to vary the thickness of the layer applied to the product.
A quick readjustment between different types of products is furthermore realised with an apparatus according to the invention where the lower part of the slat is attached releasably to an upper part of the slat. By providing spring loaded, pivotable hooks on the lower slat for engaging pins on a link connection between the upper and lower part of the slat an exchange of the lower part may be performed with a very quick action. Hereby the lower part of the slat with means for suspending products is exchanged without the use of tools and with a limited consumption of time.